1. Field
One or more embodiments of the invention relate to a zoom lens having a vibration prevention function and an electronic device using the zoom lens, and more particularly, to a zoom lens having a vibration prevention function which is used in, for example, a video camera, a digital camera, a mobile phone with a built-in camera, or a personal digital assistant.
2. Description of the Related Art
Various zoom lenses have been suggested which include a mechanism (vibration prevention mechanism) for compensating for image vibration due to unwanted vibration that is transmitted to a photographing system. For example, zoom lenses are known to compensate for image vibration due to vibration by moving some of the lens groups included in an optical system (zoom lens) in a direction perpendicular to an optical axis.
As one of such types of zoom lenses, a conventional zoom lens includes, in order from an object side to an image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power, in which the first lens group and the third lens group move toward the object side when zoom is changed from a wide angle end to a telephoto end, and which compensates for image vibration due to vibration by moving the second lens group in a direction perpendicular to an optical axis (for example, Japanese Patent Publication No. Hei 7-27977).
In addition, in the a conventional zoom lens, the second lens group includes two negative lens groups in order from the object side and compensates for image vibration due to vibration by moving the lens group of the two negative lens groups closer to the image side in a direction perpendicular to the optical axis (Japanese Patent Publication No. Hei 7-325272).
However, optical systems that have been recently suggested have a long focal length at the wide angle end. Accordingly, when an optical system uses a standard zoom lens including a wide angle area, an optical performance may not be satisfactorily designed.